It's fairly common that people think they can do what directors can and that they'd be happy to for a fraction of the pay.
I've also seen a fair few people become directors (from already high up positions) and fail miserably. Whether it's knowledge, decision-making, stress management or one of hundreds of other things, there are a lot of people who simply cannot do the job.
Just because there's not a technical qualification or easily measurable skillset as for a doctor or an engineer, it doesn't make it any less difficult a role to succeed at. The employment market (other than the unwelcome interference of the minimum wage) is reasonably free and frictionless. If the top roles at companies weren't worth a lot of money, people wouldn't be paid a lot of money for them.